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Power Bus system

4223 Views 29 Replies 10 Participants Last post by  SPROGman
Hi,
I am confused regarding the Bus systems people use. I have looked at a few other threads and its confused me more.

Anyway. if I explain what I think a bus system is then could anybody enlighten me as to weather or not I am correct?.........

Basically cable running every couple of metres soldered to the edge of each rail and constantly going around the track, starting from track source? I did a search on the net for bus kits and one DCC kit I saw involved crimps and all sorts of stuff, not what I expected.


(wires in photo not soldered to track - just placed for photo reference)

The wire I am using is the same specification that comes with DCC sets. I have stripped the ends of the cable to approx 10mm and tinned them to stop them spraying out.

Any help will be greatfully appreciated.
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I have to agree with Robert. The best connection is always going to be a correctly made and soldered joint. Crimps, screw down connector blocks or just twisting wires are all likely to be sources of trouble in the future.

On a medium to largish layout I would recommend nothing smaller than a conductor size of 2.5mm and an even larger size if the layout is more than 4 plus mtrs long. I used some twin & earth (T & E) 2.5mm cable removing the outer sheathing and then laying the two insulated conductors around the layout and stripping back a short length of the insulation wherever I need to make a soldered connection to any droppers or other accessories etc. As a bonus, I also ran the 1.5mm bare former earth wire for the T & E cable around the layout as this is my common return conductor for everything that's not DCC


A couple of pictures and further explanation are on my site DCC Wiring

BTW...Dynamite26, your link to Rapid fails to specify which of the five sizes of conductor you're using as a power bus?
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Hi Breaston
Just remember to always keep the same rail to the same colour bus wire throughout e.g. Blue bus wire always connects to the outer (or inner - your choice) rails etc. This is easily forgotten especially where a continuous loop of track is involved!
Hi Smokeyone
As dbclass50 states keep them very short.
You didn't say which Fleischmann system your using but if its the 6803C this is only rated at 1.5 amps so the thinner wire would be ok here. The 6801 twin doesn't seem to have an output rating on their web site so its hard to comment about. But as its dual control I would expect it to be around 3 plus amps.
The idea of the larger bus wire is two fold really.
1) It allows plenty of current carrying capacity.
2) On a larger layout it helps overcome volt drop.
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I'd buy a 50mtr drum of either 1.5mm T & E or 2.5mm T & E which cost around £16 to £22 depending very much on where its purchased and then remove the outer grey sheath (It pulls off very easily!). You're then left with a Brown and Blue insulated pair of conductors and a bare earth wire. You run the two insulated conductors around the layout and tap into them wherever needed. You can discard the bare earth wire or do as I have done and run it around the layout with the other two and use the former earth wire as a common return conductor for all non DCC items.
Cable like this...(Not necessarily the cheapest on offer though!)
1.5mm T & E
2.5mm cable
Droppers can be 16/02mm flex purchased in a 10mtr long hank with the same two conductor colours as the main bus wires (Brown & Blue).
Total cost around £18 to £25 maximum.


If your lucky and know anyone who's having a house rewire or know a local electrician you will probably be able to have for free some old Red & Black insulation 2.5mm cable in reasonable lengths, which without to much trouble, this can be soldered up to make a longer conductor lengths if needs be
:
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QUOTE I can never understand the us of solid core (new or scrap) twin & earth cable.
Scrap if free

T & E is so easy to come by..... All DIY stores sell it, OK prices may vary, but that's the buyers choice where to purchase from...
Best of all its easily obtainable - so you can buy now and no waiting to order flexible from a remote suppler and waiting etc.
Once in palce 2.5mm solid is very easy to strip the insulation from whenever a dropper is needed to connect to it - Run a craft knife around the insulation and slice off 15-20mm or so . Flexible conductors are very much harder to strip along their length. It keeps flexing then the knife digs into the soft wires and fractures a few conductors so you end up with 2.5 cable reducing it to around 1.5mm if you're not careful.


If you're using 100mtrs of cable for a DCC bus you have one big layout!! Most layouts wouldn't want anywhere near this amount. 20 to 25 Mtrs easily doing a 7 x 6 Mtr (21 x 18 feet approx) layout and that's big for the UK.
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Sorry, I have to completly disagree.
For a fixed layout, solid mains conductor for a DCC bus is ideal. (Portable's are a little diferent and need a little bit of movement thats offered by flex! but were refering to home layouts that are in the main fixed)
You dont have to buy 50 or 100Mtr drums of mains cable as its sold in shorter 'pre-cut' or 'cut it yourself' lengths. So a big saving can be made if you only need say 10Mtrs.

Senario Saturday morning I need to install my DCC bus. Now I can go to my local DIY store/Wilkos etc and buy immediatly my cable (Most towns have at least one store that sells mains cable), I take it home and install it

Alternativly I can order by phone or the internet from wherever.... Now, the order wont be processed until Monday, posted off, if its in stock, on Monday p.m.and perhaps arrive with me if I'm in luck Tuseday or more likely Wednesday. Max 5 days have past by.

The solid wire has been installed, conencted up and in use all ready by Saturday p.m. or Sunday perhaps


I would, for the home layout, recommend solid conductor bus wire (stripped from mains cable) everytime - Its Cheap (or free perhaps), easy to obtian, simple to instal and very easy to connect onto and solder onto once installed


Sorry we dont agree, but thats life
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